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Invasive Streptococcus pneumoniae disease is preceded by asymptomatic nasopharyngeal carriage. Measuring carriage in healthy populations provides data on what serotypes are present in communities, which is of interest in the era of polyvalent pneumococcal conjugate vaccines. Nasopharyngeal swabs from a survey of 682 and 800 healthy children in 2016 and 2018, respectively, were analyzed by culture and Quellung reaction to determine rates of carriage and serotypes. All swabs from 2016 and 300 randomly selected swabs from 2018 were then analyzed using real-time semi-quantitative PCR (qPCR) to detect S. pneumoniae gene targets lytA, piaA, and SP2020 and determine serotype. There were 71 (10.4%) and 68 (8.5%) culture positive samples in 2016 and 2018, respectively. All of these were also positive by qPCR except one that was equivocal. In total, 46.0% of 2016 swabs were positive by qPCR. In 2018, results from the selected sample extrapolated to the complete sample showed 49.0% positive by qPCR. PCV13 serotypes were detected in 29.3% and 21.7% of S. pneumoniae qPCR positive samples from 2016 and 2018, respectively; compared with only 8.4% and 6.0% PCV13 serotypes detected by Quellung reaction in culture positive samples. Compared with culture, qPCR detected S. pneumoniae more frequently. Further, qPCR serotyping detected PCV13 serotypes in a larger proportion of samples than culture and Quellung reaction did, showing that, despite established universal childhood PCV13 immunization, vaccine serotypes can still be detected in a large proportion of young children.

Background The objective was to compare commercial assays on clinical specimens for Mycoplasma genitalium (MG) detection and macrolide resistance mutation (MRM) frequency. Methods Three self-collected vaginal swabs (VS) and a first-void urine (FVU) from 300 consented women were tested by Aptima MG (AMG), ResistancePlus MG (RPMG) and Seeplex STD6 ACE (STD6) for detection of MG. Aptima MG and STD6 MG positives were tested for MRM using MG 23S rRNA polymerase chain reaction with Sanger sequencing (23SMGSS) compared with MRM determination in the RPMG assay. Unique AMG positives were tested with confirmatory Aptima assays. Results M. genitalium prevalence ranged from 7.1% to 19.7%, influenced by the assay used and the specimen tested. Overall agreements for MG detection were 96.3% (κ = 0.91) for VS and 93.3% (κ = 0.72) for FVU between AMG and RPMG with lower agreements with STD6. Using a rotating reference standard, sensitivities on VS and FVU were 100% and 100% for AMG, 100% and 83.3% for RPMG, and 54.2% and 48.4% for STD6. Specificities were high for RPMG and STD6 and AMG detected extra positives, most of which were confirmed. Macrolide resistance mutation frequency rates testing VS and FVU were 50% (24/48) and 58.1% (18/31) by RPMG compared with 52.5% (31/59) and 23.5% (12/51) by 23SMGSS. MRM overall agreements between RPMG and 23SMGSS were 73.2% (κ = 0.41) for VS and 76.0% (κ = 0.52) for FVU. Conclusions Aptima MG detected more cases of MG infections. ResistancePlus MG detection was more effective on VS than on FVU. Seeplex STD6 ACE performance was inferior. The MRM detection component of RPMG agreed with results from 23SMGSS most of the time.

SARS-CoV-2 variants of concern (VoC) have been increasingly detected in clinical surveillance in Canada and internationally. These VoC are associated with higher transmissibility rates and in some cases, increased mortality. In this work we present a national wastewater survey of the distribution of three SARS-CoV-2 mutations found in the B.1.1.7, B.1.351, and P.1 VoC, namely the S-gene 69-70 deletion, N501Y mutation, and N-gene D3L. RT-qPCR allelic discrimination assays were sufficiently sensitive and specific for detection and relative quantitation of SARS-CoV-2 variants in wastewater to allow for rapid population-level screening and surveillance. We tested 261 samples collected from 5 Canadian cities (Vancouver, Edmonton, Toronto, Montreal, and Halifax) and 6 communities in the Northwest Territories from February 16th to March 28th, 2021. VoC were not detected in the Territorial communities, suggesting the absence of VoC SARS-CoV-2 cases in those communities. Percentage of variant remained low throughout the study period in the majority of the sites tested, however the Toronto sites showed a marked increase from ~25% to ~75% over the study period. The results of this study highlight the utility of population level molecular surveillance of SARS-CoV-2 VoC using wastewater. Wastewater monitoring for VoC can be a powerful tool in informing public health responses, including monitoring trends independent of clinical surveillance and providing early warning to communities.

The sudden emergence and spread of Monkeypox in non-endemic parts of the world is currently not well understood. Infections are often mis-diagnosed and surveillance strategies are scarce. Wastewater-based surveillance (WBS) of human Monkeypox virus (MPXV) can help supplement our current clinical surveillance and mitigation efforts. WBS has shown to be an effective tool in monitoring the spread of other infectious pathogens, such as SARS-CoV-2 and its variants, and has helped guide public health actions. In this study, we describe how WBS can be used to detect MPXV in wastewater. We conducted WBS for MPXV in 22 wastewater treatment plants (WWTPs) over a period of 14 weeks. Nucleic acids were extracted using the MagAttract PowerMicrobiome DNA/RNA extraction kit. Three real-time qPCR assays were assessed for the detection of MPXV in wastewater. These included the G2R assays (G2R_WA and G2R_G) developed by the Centers for Disease Control and Prevention (CDC) in 2010, as well as an in-house-developed assay (G2R_NML). The G2R_WA assay was designed to detect the West African clade of viruses while the G2R_G (generic) assay was designed to detect both the Congo and West African clades (re-named to clades 1 and 2 respectively). The G2R_NML assay was designed using reference genomes of the 2022 MPXV outbreak. Our results show that all three assays have similar limits of detection and are all able to detect the presence of MPXV in wastewater. Following detection through real time qPCR, Sanger sequencing was performed on the resulting amplicon products, with the assembled contigs then undergoing analysis using nucleotide Basic Local Alignment Search Tool (BLAST). Due in part to the longer amplicon size of the G2R_NML assay, a significantly greater number of positive detections were identified as originating from MPXV compared to the CDC G2R assays. The ability to detect trace amounts of MPXV in wastewater as well as obtain Sanger sequence confirmation, has allowed for the successful surveillance of this virus in wastewater.